Infiniti revealed the Emerg-E sports-car concept on Tuesday at the Geneva motor show. The slick-looking coupe will have a pair of 201-hp Evo Electric motors that drive the rear wheels. The motors direct their power to a single-speed XTRAC transmission. Four inverters control the motors and the energy regeneration under braking. A lithium-ion battery sits behind the seats collecting power.

When the juice runs out, a 1.2-liter engine kicks in to charge up the battery. Infiniti worked with Lotus on the range extender. It produces 35 kilowatts of power at a peak of 3,500 rpm. Infiniti says the battery can provide 30 miles of range without using gasoline.

The Infiniti Emerg-E has a lightweight, extruded-aluminum chassis with carbon-fiber body panels. That leads to a curb weight of 3,523 pounds. The car was developed with racing specialists Lola Composites in the United Kingdom. Infiniti says it will explore the use of the ultralight material for future vehicles.

Drag was reduced to 0.34 Cd with the flowing bodywork. Infiniti says that once downforce was taken care of, cooling became a problem in EV mode. The company added a number of subtle air intakes and extractors to correct the problem.

The Emerg-E was developed under the direction of Nissan design chief Shiro Nakamura. The project was partly funded by the U.K. government's Technology Strategy Board, whose mission is to expedite the use of low-carbon vehicles onto U.K. roads. The board provided Infiniti a chance to work with many innovative suppliers and OEMs. That was how Infiniti discovered that Lotus was working on a range extender and decided to collaborate.

The Emerg-E is the third of a trilogy of concept cars for the company, following the Essence and the Etherea. Infiniti says the three concepts embody three themes around which the company designs cars--energetic force, seductive aura and dignified intelligence.

Infiniti never planned for the Emerg-E to be a mid-engine car but relished the challenge when it came to package constraints and the distribution of weight.

"We wanted to make it elegant yet dynamic, to show graceful power," Nakamura said. "Midship cars are usually more crude; this is like silk wrapping over the wheels."